Optoelectronics is the study and application of light-emitting or light-detecting devices. It is widely considered a subdiscipline of photonics, which is the study and application of the physical science of light.1
This fast-emerging technology field applies electronic devices to sourcing, detecting, and controlling light. It may be used for everything from military applications to telecommunications to medicine.
Theory of Optoelectronics
Optoelectronics is the specific discipline of photonics that focuses on light-emitting or light-detecting devices. This may include components used to detect or emit radiation in the visible or near-infrared regions of the electromagnetic spectrum.
Optoelectronics’ function is to manipulate the photovoltaic effect of materials, i.e., light-matter interaction. All optoelectronic devices are based on photons’ photovoltaic effect, which is the excitation of electrons in the material.2
Photo energy is absorbed into electrons when a light beam strikes a photoelectric surface. If this energy exceeds the electron’s bandgap, it is emitted from the material.
About Optoelectronic Devices
Many optoelectronic devices are based on semiconductors like silicon, which feature electronic properties that fall in between a conductor and an insulator.3 These semiconductors exhibit ideal band gap energies for absorbing near-infrared and visible light, and their electrical conductivity is also ideal for many applications.
In recent years, semiconducting nanocomposites have revolutionized optoelectronics devices. Such materials can improve gas sensor sensitivity, laser intensity, biosensor sensitivity, and optical detection response.4 These semiconductors are often used in consumer, military, and industrial products like photoresistors, photodiodes, and laser diodes.
Types of Optoelectronic Devices
The types of optoelectronics include the following:
Photodiode
A semiconductor light sensor that generates a voltage or current when light hits the junction. When a photon with energy strikes the semiconductor, it creates an electron, which diffuses to the junction and forms an electrical field. This may be used in circuits or for applications like medical instruments, safety equipment, cameras, and communication devices.5
Light-Emitting Diode (LED)
An LED produces light by passing an electric current through a semiconductor material, emitting photons through electroluminescence (the conversion of electrical energy into light).6 The energy bandgap of the material determines the color of the light. LEDs are desirable for their low energy needs and low heat emission, as well as their longevity, for medical devices, instrument panels, fiber-optic communication, indicator lights, and consumer electronics.
Optical Fiber
An optical fiber is a transparent fiber consisting of plastic or glass, often slightly thicker than a human hair. The fiber acts as a waveguide (or light pipe) to transmit light between the fiber’s two ends. Optical fibers have a core, cladding, and jacket layer. For a glass fiber, the core layer consists of silica and acts as the light-transmitting layer, while the cladding, also made of silica, serves as the protective layer. The jacket is the non-optical layer of polymer that protects the core and cladding from environmental damage.7 Sensors, biomedical devices, telecommunications, and other products use fiber optics. They have advantages of higher bandwidth, lower signal degradation, flexibility, and cost-effectiveness.
Solar Cells
These cells are electronic devices that convert the sun’s energy into electricity. When sunlight, composed of photos, reaches the silicon atoms of a solar cell, they lose electrons and transfer energy to an external circuit to produce electric power.8
Laser Diode
A laser is a monochromatic, coherent, and directional light source that converts electrical energy into light energy, like LEDs. When voltage is applied to the junction, the electrons experience population inversion. The emitted photons reflect back and forth to create more electron pairs, creating a coherent beam.9 Consumer and industrial devices such as laser printers, surgical instruments, fiber optic communications, and LANs use lasers.
Looking to the Future of the Industry
Market Insight Reports estimates the optoelectronics market will grow at a rate of 10.25 percent by 2024.10
As a considerable part of the global semiconductor market, the growth is noticeable in the following areas:
- Increasing demand for LEDs. LEDs are the industry standard for electronic devices and display technology due to higher resolution and better performance. LEDs are virtually everywhere, from automotive lighting to medical devices.
- Growing consumption of advanced manufacturing and fabricating technologies drives the consumption of optoelectronic components in the industrial sector and vision systems.
- Demand for electric and autonomous vehicles, which use optoelectronic devices.
- Consumer electronics demand and consumption in the Latin America and Asia-Pacific regions and their reliance on optoelectronics components.
- Demand for laser products globally, which use laser diodes.
Key factors in the growth of the optoelectronics industry include:
- Increasing investments in smart infrastructure and automation technologies.
- The U.S. Department of Agriculture’s National Institute of Food and Agriculture has sanctioned grant funding to research the use of LEDs to provide efficient light sources for plant photosynthesis.
- The U.S. plans to invest in local manufacturing, including semiconductor manufacturing facilities.
Optoelectronic Devices at Apollo Optical Systems
As a leader in optics manufacturing, Apollo Optical Systems is on the cutting edge of the evolving optics industry, including optoelectronic devices and their applications in different markets. We have both optical and mechanical design under one roof, allowing for integrated optomechanical solutions.
Contact us today to discuss your custom optics design!
Sources:
[1] https://www.sciencedirect.com/topics/chemistry/optoelectronics[2] https://www.sciencedirect.com/topics/engineering/photovoltaic-effect
[3] https://www.rp-photonics.com/optoelectronics.html
[4] https://www.sciencedirect.com/topics/engineering/optoelectronic-device#:~:text=Optoelectronic%20devices%20are%20electrical%2Dto,such%20devices%20in%20their%20operation.%E2%80%9D
[5] https://www.sciencedirect.com/topics/physics-and-astronomy/photodiodes
[6] https://www.britannica.com/technology/LED
[7] https://www.sciencedirect.com/topics/engineering/optical-fibers
[8] https://www.sciencedirect.com/topics/materials-science/solar-cell
[9] https://www.sciencedirect.com/topics/materials-science/laser-diode
[10] https://www.businesswire.com/news/home/20190621005446/en/The-Global-Optoelectronics-Market-to-2024-Projecting-a-CAGR-of-10.25—ResearchAndMarkets.com